An Infinitely Long Cylinder with a Radius of 1 $\rho$ = Ar, Where a = 10

Multiple Choice

An infinitely long cylinder with a radius of 1.0 cm has a charge density that is proportional to the distance from the axis of symmetry, $\rho$ = ar, where a = 10.0 C/m⁴. The charge per unit length within the cylinder is

A) 12 $\mu$ C/m.
B) 21 $\mu$ C/m.
C) 35 $\mu$ C/m.
D) 5.0 $\mu$ C/m.